Copper futures had an eighth straight decline, the longest losing streak since 2014, amid persistent signs of oversupply in the market.

Production of the refined metal outpaced consumption by 105,000 metric tons in July, the International Copper Study Group said in a statement Thursday. That’s a swing from a deficit of 60,000 tons a month earlier. Output in China will rise to 9.8 million metric tons by 2020, from 7.96 million in 2015, the Ministry of Industry and Information Technology said Wednesday.

The decline in copper “is more to do with producers not sticking to production cuts in metals,” especially in China, Michael Turek, the head of base metals at BGC Partners Inc. in New York, said in an e-mail.

Copper futures for December delivery slipped 0.4 percent to settle at $2.096 a pound at 1:11 p.m. on the Comex in New York, the longest slump since March 2014. On the London Metal Exchange, copper for delivery in three months fell 0.4 percent to $4,652 a metric ton ($2.11 a pound).

China’s aggregate financing, the broadest measure of new credit, reached 1.72 trillion yuan ($255 billion) last month, exceeding estimates and escalating concerns over a property binge and the pace of debt expansion.

“The other concern is that while Chinese growth is quite decent, what will the authorities do to reign in another developing bubble and resultant systemic debt risk?” Turek said.